>
> Hello Paul-
>
> So the cause of my leaking oil has been found. I have determined
that
> quite a few of the tapped oil pan bolt holes in AL parts have been
> stripped. I have not surveyed all the bolts - I'll be pulling the
> engine off again to do that on Tuesday. But I did find 4 already
that
> are stripped. I pulled the bolts out & they are fine. But when
> inserted, they cannot be torqued to the spec - they spin & spin...
>
> So I suppose I could thin some JB Weld and re-tap the holes, but
given
> my tapping skills, that sounds like a recipe for disaster. I was
> thinking instead of cutting the heads off of some appropriately
> sized AN
> bolts, flooding the bolt holes with JBWeld, and then inserting the
> bolts
> head-side first. Since the pan only calls for ~ 8fp of torqued, I
> figure this is a simple and reliable way to get studs for the
stripped
> holes that I can then put metal stop-nuts on to secure the pan.
>
> Comments?
>
> Mark (Rocky Mtn High)
>
> You must of read my mind. I was just thinking about your engine.
>
> No no don't do that. Get some helicoils and a special tap.
> I am sure you can do it if you use the proper drill.
> Use google to check for the drill sizes.
> McMaster also gives the drill sizes on the web site.
>
>
http://www.emhart.com/products/helicoil.asp
>
http://www.roadstarmagazine.com/modules.php?
> name=News&file=article&sid=233
>
> In Mcmaster Carr speak they are called "Helical Inserts".
> Available in both metric and English sizes. Come in a kit with the
> drill
> and special tap. I think those pan bolts are 6 mm.
>
> Also "Thread Inserts" that require a some what larger installation
> holes.
>
> Other than the oil leak how is the p-port engine running.
>
> Paul Lamar ...No rotor no motor.
I have also found several stripped threads in the same location. If
the holes are already stripped, then helicoils are the answer.
Small threads in aluminum are easy to strip. I think it would be a
good idea to run a clean out tap whenever reinserting these bolts and
use a torque wrench. Jerry
I was doing research on this on some machinists sites & came across the
suggestion to braze the stripped hole using a certina product. Here's a
snippet from their website:
Thread Repair - Helicoil Thread Repair Alternative
Thread repair is easy with the HTS-2000 second-generation
brazing rod. If you're looking for a Helicoil thread repair
alternative you've come to the right place. With our
industrial-strength brazing rod, simply fill a hole with the
brazing rod material and drop a hot steel bolt into it. When
cool, the steel bolt can be backed out and new threads are
produced.
You probably know that sickening feeling already. You've
tightened a bolt almost as tight as it can go and you give
it that one last twist "just for good measure" and then you
feel the wrench spinning freely and loosely. You've stripped
the threads. With our HTS-2000 brazing rod, you can complete
your thread repair in minutes.
The HTS-2000 is permanent, erosion resistant and can be done
with any torch. Three times stronger and more flexible than
the first generation rods, the thread repair made with our
product is stronger than the original material.
Simpler to use than Helicoil, our HTS-2000 brazing rod can
repair threads for many automotive, aerospace, military and
industrial applications. Unlike Helicoil, there are no
inserts, taps, gages and tang break-off tools to mess with.
As with Helicoil, though, you will most likely need an
oversized drill bit to drill out the hole, first.
Instead of placing inserts into the hole, use a torch and
drop some off our high-tech brazing rod material right into
the hole. Heat the steel bolt to 750-degrees or above and
drop the bolt into the hole. Let the metal cool for 15 - 30
minutes and then using a wrench, back out the steel bolt
from the hole. Your thread repair is complete. You've just
repaired a thread faster, more efficiently and stronger than
a Helicoil thread repair.
The HTS-2000 second-generation brazing rod requires no flux,
is stronger than the base metal and melts at 500-degrees
below that of aluminum. No welding machine is needed as any
torch such as propane, butane, mapp, or an oxy-acetylene
will do. For expert thread repair, you don't have to be
expert to use our high-end brazing rod.
See the video for more details.
The video is quite impressive. Anyone have thoughts on this before I go
out tomorrow & buy some inserts?
Mark Rocky Mtn High
Mark,
Stick to PROVEN systems of repair. To do it right, either use
Helicoils (not Brand" X") or drill and tap all the holes to the next
size; ie 6mm to 8mm. Resizing the bolts means you will also have to
enlarge the pan holes. You can also use Allen Head bolts if there
are tight locations for placing a socket on the head of the larger
bolt.
For taping a hole in aluminum, use kerosene or a light oil for
lubrication. Be sure to back off your tap at least a half turn for
every turn in with the tap to clear the cuttings. Air helps to blow
away the cuttings. Practice on some aluminum scrap until you get
the feel of it.
When torquing bolts, be sure to use a torque wrench in the range of
the of the specification. A 0 - 600 inch-pound torque wrench is too
large. For a 100 inch-pound torque, a 0 - 200 inch - pound range
wound be much better. Try Harbor Freight for an inexpensive torque
wrench; a beam torque wrench would be fine. Probably a 1/4 " drive.
NOTE!!! we are talking about an INCH - POUND torque wrench, NOT a
Foot-pound wrench. 96 in-lbs equals 8 ft-lbs!!!
If you think "If a little is good, More is better". You might as
well get it done faster and use a 1/2" impact wrench at 160 psi.
Joel
Joel I totally agree on using a good inch pound wrench. The 15-120 in/lb
Snap-on wrench has been in the tool box for 20 years. Totally disagree
on the heli-coil. Heli-coils are brand-x as far as I'm concerned. They
have been used successfully, yes. But they pull out and unwind. Check
out the Time Sert, and you will never go back. IMHO
Bill Jepson
PS. The Kawasaki Z-1 and KZ1000 cam shaft cap bolts were torqued to
88-95 in/lb. on some of the poor castings they would fail even when
torqued correctly the 3rd or 4th time. WRJ
There is one problem in this application Bill. there is not enough meat
around the hole for an insert. There is only 16 MM of meat beyond the edge
of the hole. That is marginal for an insert IMHO.
Paul Lamar ...No rotor no motor.
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